Lubrication system for pipe bursting

Abstract

A pipe pulling lubrication apparatus includes a pipe anchor having an anchor body. The anchor body includes a first coupling feature near an anchor body proximal portion and a distal pipe coupling feature near an anchor body distal portion. The distal pipe coupling feature is configured to couple and position a replacement pipe exterior surface near an anchor body exterior surface. The lubrication apparatus further includes a lubrication system including a lubricant conduit extending within the anchor body from the distal pipe coupling feature toward an anchor body intermediate portion between the first coupling feature and the distal pipe coupling feature. The lubrication system includes a lubricant distributor having one or more lubricant passages extending from the lubricant conduit toward the anchor body exterior surface, the lubricant distributor is configured to deliver a lubricant to the replacement pipe exterior surface.

What is claimed is: 
     
       1. A pipe breaking assembly, comprising:
 an expander having a front opening for a pulling cable; 
 a cutter rotatably coupled in front of the expander; 
 a cable gripping anchor including a number of tapered anchor jaws located in the expander; 
 a replacement pipe anchor located at a back end of the expander, the replacement pipe coupling adapted to hold a trailing replacement pipe; and 
 an expander coupling attaching the replacement pipe anchor to the expander, wherein the expander is rotatable relative to the pipe anchor about a long axis of the expander, an wherein the expander coupling includes a fastener enclosed within the pipe breaking assembly. 
 
     
     
       2. The pipe breaking assembly of  claim 1 , wherein the cutter is rotatably coupled in front of the expander by a ball and socket joint. 
     
     
       3. The pipe breaking assembly of  claim 1 , wherein the expander coupling includes a bolt oriented axially within the pipe breaking assembly. 
     
     
       4. The pipe breaking assembly of  claim 1 , wherein the cutter includes four blades. 
     
     
       5. The pipe breaking assembly of  claim 1 , further including a lubricant passage exiting the pipe breaking assembly in front of the expander. 
     
     
       6. The pipe breaking assembly of  claim 1 , wherein a diameter of the cutter is smaller than a diameter of the expander. 
     
     
       7. The pipe breaking assembly of  claim 1 , wherein the replacement pipe anchor includes a number of serrations to grip an interior surface of a pipe to be replaced. 
     
     
       8. The pipe breaking assembly of  claim 7 , wherein the number of serrations include screw threading. 
     
     
       9. A pipe breaking assembly, comprising:
 an expander having a front opening for a pulling cable; 
 a cutter forming a ball and socket joint with the expander wherein the cutter is configured to abut a front end of the expander without direct coupling, wherein pulling forces are transmitted in compression through the ball and socket joint; 
 a cable gripping anchor including a number of tapered anchor jaws located in the expander; 
 a replacement pipe anchor located at a back end of the expander, the replacement pipe coupling adapted to hold a trailing replacement pipe; and 
 an expander coupling attaching the replacement pipe anchor to the expander, wherein the expander is rotatable relative to the pipe anchor about a long axis of the expander, an wherein the expander coupling includes a fastener enclosed within the pipe breaking assembly. 
 
     
     
       10. The pipe breaking assembly of  claim 9 , wherein the cutter includes four blades. 
     
     
       11. The pipe breaking assembly of  claim 9 , further including a lubricant passage exiting the pipe breaking assembly in front of the expander. 
     
     
       12. The pipe breaking assembly of  claim 9 , wherein the replacement pipe anchor includes a number of serrations to grip an interior surface of a pipe to be replaced. 
     
     
       13. The pipe breaking assembly of  claim 12 , wherein the number of serrations include screw threading.